An active interrogation technique for a 16-cascaded wavelength-division multiplexing fiber Bragg grating sensor system is proposed. The system has been demonstrated using a combination of a feedback control technique, which makes the transmission of an employed tunable F-P filter track the Bragg wavelength of the interrogated sensor automatically, and a technique for choosing the output wavelength of a ring- compounded-cavity fiber laser by tuning the applied voltage of the filter. Demodulated by using an unbalanced scanning Michelson interferometer, a sensitivity of 1.682 Deg/(mu) (epsilon) has been achieved.